This combo of a navy crew-neck t-shirt and jeans is an interesting balance between comfortable and dapper. If you need to easily class up your outfit with a pair of shoes, why not rock a pair of navy suede driving shoes? This pairing should erase any doubts you had about dressing casually as a mature gent.
Marry a navy crew-neck t-shirt with jeans to create a truly sharp and modern casual outfit. When in doubt as to what to wear in the shoe department, round off with a pair of white canvas low top sneakers. This pairing shows that even well into your 50s your sartorial options are still looking good.